I'd image for real full dive vr it would look like the approach from SAO: aliciatization*. If you could use a brain or brain stem implant to put the vr feed into the ocular nerves and have the digital vr come in as natural "sight" through the visual pathway. That would be your best bet. You could add in electronic signals through the same implant to do your best to replicate other sensory inputs like the sensation of walking or movement but I don't think you would have much luck, this would probably be the trickiest part. This would probably require some sort of twilight anesthesia like drug administration to separate the consciousness from the body. It would only be done in a medical lab. Until we have full digitalization of consciousness. We will have nice haptic feedback rigs in the future but "full dive" or as close as we can get will only be done under medical supervision imo.